The claim that one of India's greatest treasures actually has a Hindu, rather than Muslim, origin goes back almost 20 years. Pawan Sharma / AP Photo

India's most famous monument has found itself dragged through the country's courts. The Taj Mahal is at the centre of a bizarre court case in India, brought by six lawyers who contend that the Taj Mahal, rather than a mausoleum built by the Mughal emperor, Shah Jahan, in memory of his favourite wife – as four centuries of Indians have believed – in fact started life as a Hindu temple. The court asked the Archaeological Survey of India, the main government body charged with researching and protecting the cultural heritage of the country, to give an opinion. The institution was scathing and called the claims “concocted”.

The claim that one of India's greatest treasures actually has a Hindu, rather than Muslim, origin goes back several years to a fringe Indian writer called PN Oak, who made his claim in a 1989 book. Oak wrote a series of bizarre pamphlets in which he claimed Hindu origins for most of India's – and indeed many of the world's – monuments, including the Vatican. He even claimed that Christianity was actually derived from Hindu practices – apparently on the strength of a pun, “Krishna-neeti” – and that it was taught to Jesus Christ when he – so Oak contended, without citing evidence – visited India.

Unsurprisingly, Oak's work was not widely read. He died in 2007, but not before taking his claims to India's supreme court, where they were dismissively thrown out. In the later years of his life, however, Oak's work was rediscovered by Hindu nationalists, who saw in his fringe, conspiratorial claims a chance to assert Hindu supremacy against Muslims, Christians and other religious minorities across India. When the court case was first filed in 2015, it asked that all Muslims be stopped from offering prayers at the Taj Mahal and that only Hindus be allowed to do so.

This particular cultural skirmish is not the first instance of rising nativism in India, nor will it be the last. Narrow nationalism appears to be a disease of this particular moment, and not merely in India. Hindu nationalism is born of the same social and historical forces as Islamism in the Middle East, both seeking strength against outside influence by casting back to an assumed “pure” history.

What seem like historical questions, therefore, are in fact questions about the politics of the moment. And they are happening all across the world.

In Iraq, Shia communities have sought to undermine Sunni claims to cities like Samarra, and Kurdish groups have sought to do the same to mixed cities like Kirkuk. ISIL, of course, sought to remove the influence of any minority faiths, such as Yazidis, and even Sunni interpretations they didn't like. In Israel, Palestinian claims to monuments, towns and cities are regularly attacked. The many simmering national tensions of the Balkans regularly seek to undermine the historical claims of their neighbours. Most dramatically, Russia's seizure of Crimea was accompanied by an intellectual effort to reduce Ukraine's claim to the region – indeed Russian nationalists continue to make historical claims against the Baltic states.

Everywhere that such nationalism rears its head, it begins by denying the historical influence of other groups, ethnic, religious or cultural.

This can even happen before that influence is widely accepted. In the United States, at the moment, the arguments over confederate statues are actually part of a wider fear that white Americans have over the influence of non-whites. Even before the monuments to African-Americans or female pioneers have even been erected – or, indeed, even discussed – some white Americans are already fearful that their monuments are being torn down.

To understand this better, it helps to look at a bit of the context surrounding confederate statues. These were statues and monuments erected to figures from the era of the confederacy, the group of American states that seceded in order to maintain slavery and which eventually lost the American civil war. Over the past couple of years, protests have taken place over symbols of that period being displayed in public areas, with the result that many have been taken down across the US. The issue, which can seem like a peculiarly American debate, received widespread attention last month when a protest over the removal of a statue in Virginia turned violent. It sparked a debate across the western world: in Canada, there has been a public debate about monuments to figures with links to the slave trade; in the UK, over Nelson's column.

At its heart, this is a question of identity, similar to what is taking place in India, Israel, Iraq and elsewhere. The symbols of the Confederacy mean something to Americans today, beyond their historical context. For those opposing the statues, they are a symbol of white supremacy, a reminder – perhaps a celebration – stamped in iron in the public space, of a particularly ugly time in US history, and as the US evolves, they believe those symbols ought to be removed. For those supporting the statues, even those who don't necessarily like what they represent, their removal is an erasure of a particular history, one rooted in a pastoral, bygone Southern era. Supporters – including the US president – worry that such historical revisionism has no end, and will consume even revered historical figures like America's founding fathers.

This points to what is actually taking place behind the veneer of a historical debate. The fact is that the communities which make up these countries have not yet found a way to live together. Whether it is Hindus and Muslims in India, or Sunnis and Shia in Iraq, or southerners and northerners in America, rather than finding a way to weave together their communities into a national story, these groups have adopted a zero-sum game, wanting to erase the influence of communities they dislike.

Perhaps there is a historical lesson from the era of the Taj Mahal. Not from Shah Jahan, but from his son and successor Aurangzeb. In the latter years of Aurangzeb's rule, he struggled to reconcile the Hindu and Sikh communities in his kingdom, as his predecessors had successfully done. The result was a fragmentation of his kingdom and the beginning of the end of his dynasty. Trying to build complex societies on the pillar of only one community is as bad a political recipe today as it was then.